A man has been arrested on suspicion of making or possessing an explosive item with intent to endanger life after an incident at a leisure centre.
Suffolk Police said officers were called to the centre in Sudbury at around 9.45pm yesterday to reports that a man had made threats to a staff member and thrown a small ignited item into a room.
The item was extinguished immediately and no damage was caused or anyone injured.
Officers later arrested a 33-year-old man in the town, who remains in custody.
Police have cordoned off an address in Woodhall Road, Sudbury.